It is desired for a folding bicycle to be folded into a more and more compact size. In order to reduce the folded volume of a folding bicycle, a folding joint is usually disposed under the handlebar stem of the folding bicycle. Wherein, the handlebar can be folded downwards with the handlebar stem, and after being folded, the handlebar is placed on the fork blade of the front fork. However, the fork blade of the front fork is a straight-tube as viewed from the front. When the handlebar contacts with the fork blade, it is tilt supported. Therefore, the bicycle cannot be further folded and the folded volume is still rather large.